1. Field of the Invention
The present invention relates to a crystal growing kit and method of growing crystals for educational purposes.
2. Description of the Related Art
Elementary or secondary education science curriculums often include a lab project where the students grow crystals. The current method of growing crystals from a saturated salt solution involves first mixing up a saturated solution of a salt in a deep container, such as a pint jar. Next, a piece of string with a paper clip attached to one end is suspended from the mouth of the container by tying the other end of the string to a pencil. The pencil is laid horizontally across the top or mouth of the jar so that the string and paper clip are suspended from the pencil and hang downward into the saturated salt solution. The string and or the paper clip then serve as substrate on which crystals grow as the liquid evaporates from the salt solution.
One of the problems with this current method of growing crystals is that crystal growth using this method is not predicable and sometimes crystals will not grow on the string or on the paper clip. Even if crystals do grow on the substrate, they are often not as large and perfectly grown as is desired.
Another problem with the present method is that the pencil that is used to hold the string and paper clip can roll or slip off the mouth of the container and thereby ruin the crystal growth.
Still another problem with the present method is that a large volume of liquid is needed to fill the deep jar sufficiently, making it expensive to have more than one jar available in a classroom. Thus, this method of growing crystals normally is done by the teacher as a demonstration rather than as a project that each individual student is able to do on their own.
Another problem with the present method is that it takes from four to six weeks to grow crystals.
Still a further problem with the present invention is that when crystals grow on the substrate, the crystals generally grow as multiple crystals, and production of the more desirable single crystals is rare. The single crystals are more desirable because they are easier to examine than multiple crystals.
Finally, even if perfect crystals are grown, the string is flexible and this makes it hard to handle the crystals without damaging or dislodging them from the substrate. For this reason, long term storage of the crystals that are grown on string is difficult since there is no flat surface on the substrate to which the crystals are attached and on which the substrate can rest during storage.
The present invention addresses these problems by providing a cost effective kit and method for reliably growing crystals in the classroom. The kit consists of only a disposable plastic petri dish and a piece of construction paper, making it very inexpensive. Further, the present invention is designed so that both single and multiple crystals are grown on each substrate. The crystals that are grown using the present kit and method are larger and more perfect than those normally produced by prior art classroom crystal growing methods. Because the crystals are grown on a flat substrate and within a clear petri dish, the dish and the substrate are easy to handle, and it is hard to ruin the growing crystals. Because the kit employs 25 milliliter petri dishes, the volume of saturated salt solution needed per each petri dish or student is small, thereby making it economical enough so that each student can grow his or her own crystals.
The present kit and method produces both multiple and single crystals in less than five days on each substrate so that the students can see the difference between these two types of crystalline growth and can have single crystals to examine. The construction paper substrate used in the present kits and method for the substrate on which crystal growth occurs is sufficiently strong, even when still wet, to support the crystals that grow on it so that students can handle the substrate and crystals without dislodging the crystals from the substrate. Because the substrate is strong, this allows the crystals to be stored without damage for long periods of time, for example until the next year so that the crystals can be shown to a new class of students.